Add font_scale_factor_quirk pref.

chrome/browser/chrome_content_browser_client.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chrome_content_browser_client.h"
 
 #include <set>
 #include <utility>
 #include <vector>
 
@@ skipping 164 matching lines @@
 #include "chrome/app/breakpad_linux.h"
 #include "chrome/browser/crash_handler_host_linux.h"
 #endif
 
 #if defined(ENABLE_CAPTIVE_PORTAL_DETECTION)
 #include "chrome/browser/captive_portal/captive_portal_tab_helper.h"
 #endif
 
 #if defined(OS_ANDROID)
 #include "ui/base/ui_base_paths.h"
+#include "ui/gfx/android/device_display_info.h"
 #endif
 
 #if defined(USE_NSS)
 #include "chrome/browser/ui/crypto_module_password_dialog.h"
 #endif
 
 #if !defined(OS_CHROMEOS)
 #include "chrome/browser/signin/signin_manager.h"
 #include "chrome/browser/signin/signin_manager_factory.h"
 #endif
@@ skipping 347 matching lines @@
     return;
 
   PopupBlockerTabHelper* popup_helper =
       PopupBlockerTabHelper::FromWebContents(tab);
   if (!popup_helper)
     return;
   popup_helper->AddBlockedPopup(params);
 }
 
 #if defined(OS_ANDROID)
+
 void HandleSingleTabModeBlockOnUIThread(const BlockedWindowParams& params) {
   WebContents* web_contents =
       tab_util::GetWebContentsByID(params.render_process_id(),
                                    params.opener_id());
   if (!web_contents)
     return;
 
   SingleTabModeTabHelper::FromWebContents(web_contents)->HandleOpenUrl(params);
 }
+
+float GetFontScaleMultiplier(const PrefService* prefs) {
+  if (prefs->GetBoolean(prefs::kWebKitFontScaleFactorQuirk)) {
+    // The value of kWebKitFontScaleFactor passed by Chrome for Android already
+    // includes the multiplier.
+    return 1.0f;
+  }
+
+  static const float kMinFSM = 1.05f;
+  static const int kWidthForMinFSM = 320;
+  static const float kMaxFSM = 1.3f;
+  static const int kWidthForMaxFSM = 800;
+
+  gfx::DeviceDisplayInfo info;
+  int minWidth = info.GetSmallestDIPWidth();
+
+  if (minWidth <= kWidthForMinFSM)
+    return kMinFSM;
+  if (minWidth >= kWidthForMaxFSM)
+    return kMaxFSM;
+
+  // The font scale multiplier varies linearly between kMinFSM and kMaxFSM.
+  float ratio = static_cast<float>(minWidth - kWidthForMinFSM) /
+      (kWidthForMaxFSM - kWidthForMinFSM);
+  return ratio * (kMaxFSM - kMinFSM) + kMinFSM;
+}
+
 #endif  // defined(OS_ANDROID)
 
 }  // namespace
 
 namespace chrome {
 
 ChromeContentBrowserClient::ChromeContentBrowserClient() {
 #if defined(ENABLE_PLUGINS)
   for (size_t i = 0; i < arraysize(kPredefinedAllowedSocketOrigins); ++i)
     allowed_socket_origins_.insert(kPredefinedAllowedSocketOrigins[i]);
@@ skipping 1579 matching lines @@
   if (prefs->GetBoolean(prefs::kDisable3DAPIs))
     web_prefs->experimental_webgl_enabled = false;
 
   web_prefs->memory_info_enabled =
       prefs->GetBoolean(prefs::kEnableMemoryInfo);
   web_prefs->allow_displaying_insecure_content =
       prefs->GetBoolean(prefs::kWebKitAllowDisplayingInsecureContent);
   web_prefs->allow_running_insecure_content =
       prefs->GetBoolean(prefs::kWebKitAllowRunningInsecureContent);
 #if defined(OS_ANDROID)
-  web_prefs->font_scale_factor =
-      static_cast<float>(prefs->GetDouble(prefs::kWebKitFontScaleFactor));
+  web_prefs->text_autosizing_font_scale_factor =
+      static_cast<float>(prefs->GetDouble(prefs::kWebKitFontScaleFactor)) *
+      GetFontScaleMultiplier(prefs);
   web_prefs->force_enable_zoom =
       prefs->GetBoolean(prefs::kWebKitForceEnableZoom);
 #endif
 
 #if defined(OS_ANDROID)
   web_prefs->password_echo_enabled =
       prefs->GetBoolean(prefs::kWebKitPasswordEchoEnabled);
 #else
   web_prefs->password_echo_enabled = browser_defaults::kPasswordEchoEnabled;
 #endif
@@ skipping 400 matching lines @@
   return IsExtensionOrSharedModuleWhitelisted(url, extension_set,
                                               allowed_file_handle_origins_) ||
          IsHostAllowedByCommandLine(url, extension_set,
                                     switches::kAllowNaClFileHandleAPI);
 #else
   return false;
 #endif
 }
 
 }  // namespace chrome